Typically, personal computers are provided with disk drive devices for removable media such as CD-ROMs, DVD-ROMs or MO disks. Such disk drive devices are often, for example as shown in FIG. 7, of the tray type in which a disk D is inserted/ejected by placing the disk D on a tray T that can be extended from or retracted into the main unit C of a personal computer.
Ejection of the disk D in a disk drive device of this tray of type is performed by causing the tray T to project from the main unit C by operating a mechanism that drives the tray T by manually operating an eject button E provided on the tray T. It was also possible to eject the disk D by driving the tray T by inputting a disk ejection instruction, using the OS (operating system) of the personal computer.
However, in such a disk drive device as described above, anyone at all could easily remove the disk by performing operation of the eject button or input of a disk ejection instruction. Consequently for example persons other than the authorized user of the personal computer could easily remove the disk, increasing the possibility of the disk being stolen.
Also, with a disk tray device of the tray type as described above, it was possible to remove the disk mounted on the tray by forcibly pulling out the tray, so there was a possibility of the disk being carried off even without performing a proper disk ejection operation.
In view of the above problems of the prior art, an object of the present invention is to provide a disk drive device wherein removal of the disk by persons other than the authorized user can be positively prevented.